1. Field of the Invention
The present invention relates to modular equipment in general and more particularly to modular equipment frames and the modules installed therein.
2. Description of Related Art
Modular frames are intended to accept modules that perform a variety of different functions. In the broadcast video market these functions include distribution of audio and video signals, and conversion of audio and video signals between different standards. A modular frame should be able to handle a variety of different signal types as well as the connector/cabling schemes used for the transmission of these signals.
In modular frames available today, there are three main architectures in use, fixed back-plane, mid-plane back-plane, and transition module based architecture. In a fixed back-plane architecture the modular frame has a fixed back-plane through which all connections are made. The modules mate to the frame through connectors mounted on one side of the back-plane, and all external connections (typically BNC connectors) are made through input/output (I/O) connectors mounted on the opposite side of the back-plane. Examples of this frame type are commercially available as Grass Valley Group SMS8000 series, Grass Valley Groupxe2x80x948900 series, and the Leitchxe2x80x946800 series. Fixed back-plane frames can have extremely high I/O density. Such frames can also be designed to facilitate the servicing of all active components from the front of the frame, and can provide a great deal of interconnect between modules. The major drawback of the fixed back-plane architecture frames is that the interconnect is inflexible. Connector type is predetermined by the design of the frame and may not be appropriate for all signals for all possible module types. Expensive adapters may be required to handle some signal formats.
In a mid-plane architecture approach the modular frame has a fixed mid-plane to which all connections are made. Modules plug into both the front of the frame and the rear of the frame. The rear modules contain connectors for making all external connections. Such an architecture does not offer as high of an I/O density as the fixed back-plane approach. Due to the ability to customize the connectors on the rear modules, however, it does provide for a wider range of I/O formats then the fixed back-plane approach. Since all I/O must pass through the mid-plane, signal integrity is compromised for high bandwidth signals. This problem can be solved by using active circuitry on the rear module to buffer the signal, but results in compromising serviceability of the system. An example of a modular frame with a mid-plane architecture is available commercially as the Leitch DigiBus(copyright) system.
In a transition module architecture the modular frame has a small motherboard. Each module consists of two pieces. A passive rear adapter that carries all of the connectors for external I/O and a front module that has all of the active circuitry for the module. The rear adapter mates to the motherboard from which it picks up power. The front module couples with a connector mounted on the rear adapter. An example of a modular frame with transition module architecture is available commercially as the Grass Valley Max 9000 series. This architecture allows for very flexible I/O, supporting HDTV and most other signaling formats. It also allows easy servicing of all active components from the front of the frame. However, prior implementations of this architecture do not provide for extensive interconnect between modules, and the I/O density is limited.
The present invention is directed to a modular equipment frame and modules tailored for the broadcast video market. The frame architecture maximizes connector I/O density on the rear of the frame, supports a wide range of I/O formats, provides a great deal of high speed signal interconnection between modules and allows for quick and easy servicing of all active components from the front of the frame. The frame of the present invention comprises a support structure, a motherboard having a transmission portion having a first face, and a second face. There are a first plurality of module connectors coupled to at least one of the first face and the second face. The motherboard defines a plurality of openings that extend through the motherboard from the first face to the second face. There is preferably a second plurality of module connectors coupled to the other of the first face and the second face opposite. The connectors are preferably coupled through a common connection on the transmission portion of the motherboard.
A first module of the present invention includes a body portion, an extension coupled with a first end of the body portion, a plug coupled to the extension, and an electrical connector coupled to the first end of the body portion adjacent the extension. A second module of the invention includes a body portion, an extension coupled with a first end of the body portion, an electrical connector coupled to the extension, a socket coupled to the first end of the body portion adjacent the extension, and an external connection portion coupled with the body portion and dimensioned wider than the body portion.